[Bug libstdc++/82644] Non-standard hypergeometric special functions defined in strict modes

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82644

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This is only fixed on trunk, but I think I planned to fix it for gcc-7 too.